Interview/ Prof Sachchida Nand Tripathi, dean, Kotak School of Sustainability, IIT Kanpur
Q/ Which is the biggest polluter in Delhi―vehicular emission, farm burning or construction activities?
A/ I do not think construction contributes to PM2.5. It generally gives rise to PM10, which is larger, but nevertheless it contributes to pollution. Farm burning, at its peak, contributes to PM2.5 by 35 to 40 per cent. Its contribution drops to 15 or 20 per cent if you move away from the peak. The rest is coming from the tailpipe exhaust of the vehicular fleet. There is a good contribution from industry and there certainly are also things which are coming from street burning. Cooking using wood or coal also contributes.
The last one certainly can be addressed by providing the last mile connectivity of LPG. For transport, the solutions are two-fold. One is making more people use public transport by providing end-to-end connectivity. Second, more metro and electric vehicles and buses will cut down what is coming from the exhaust pipe. And industrial monitoring is important. We need to have a proper waste disposal system so that waste does not end up being burnt on the street.
You need to understand that air quality is an issue in every country, even in the developed countries. They all have very effective air quality management systems in place. First of all, a robust air quality management system needs trained people. Second is infrastructure. You cannot manage something which you are not able to monitor. Third is creating awareness among people. You also need to create safe roads where people cycle more, walk more.
Q/ What technologies can help Delhi tackle the pollution problem?
A/ We are trying to create low-cost air quality monitoring technologies. [Because of the low cost, they can] increase the data footprint by a factor of 50. Once you get hyper local discrete information, you are able to clearly identify the hot spots. Second, using census data and making use of artificial intelligence, we are trying to identify sources that are contributing to the particular hotspot. That can enable you to take certain actions.
Q/ The Delhi government has been discussing a proposal to carry out cloud seeding. How effective can this be?
A/ What it does is accelerating the overall rain formation process in the cloud. The Chinese use cloud seeding to mitigate air pollution in Beijing. Rain is a very effective scavenger of pollutants, both particulate matter and gases. When the raindrops fall, they collect everything below it.